Open surgery is still the standard technique for most surgical procedures. It has been used by the medical community for several decades and consists of performing the surgical tasks through a long incision in the abdomen, through which traditional surgical tools are inserted. However, due to the long incision, this approach is extremely invasive for the patients, resulting in substantial blood loss during the surgery and long and painful recovery periods at the hospital.
In order to reduce the invasiveness of open surgery, laparoscopy, a minimally invasive technique, was developed. Instead of a single long incision, four to five small incisions are made in the patient through which appropriately sized surgical instruments and endoscopic cameras are inserted. Because of the low invasiveness, this technique reduces blood loss and shortens hospital stays and pain. When performed by experienced surgeons, this technique can attain clinical outcomes similar to open surgery. However, despite the above-mentioned advantages, laparoscopy requires extremely advanced surgical skills to manipulate the rigid and long instrumentation. The entry incision acts as a point of rotation, decreasing the surgeon's freedom for positioning and orientating the instruments inside the patient. The movements of the surgeon's hand about this incision are inverted and scaled-up relative to the instrument tip (“fulcrum effect”), which removes dexterity, sensibility and magnifies the tremors of the surgeon's hands. In addition, these long and straight instruments force surgeons to work in a uncomfortable posture, which can be tremendously tiring during several hours of operation and result in stress and discomfort for hands, arms and body. Therefore, due to these drawbacks of laparoscopic instrumentation, these minimally invasive techniques are mainly limited to use in simple surgeries, while only a small minority of surgeons is able to use them in complex procedures.
To overcome these limitations, surgical robotic systems were developed to provide an easier-to-use approach to complex minimally invasive surgeries. By means of a computerized robotic interface, these systems enable the performance of remote laparoscopy wherein the surgeon sits at a console manipulating two master manipulators to perform the operation through several small incisions. Like laparoscopy, the robotic approach is also minimally invasive, bringing several advantages over open surgery in terms of pain, blood loss, and recovery time. In addition, it also offers better ergonomy for the surgeon compared to open and laparoscopic techniques. However, although being technically easier, robotic surgery brings several negative aspects. A major disadvantage of these systems is related to the extremely high complexity of existing robotic devices, which are composed of complex mechanical and electronic systems, leading to huge costs of acquisition and maintenance, which are not affordable for the majority of surgical departments worldwide. Another drawback of these systems comes from the fact that current surgical robots are very large, competing for precious space within the operating room environment and significantly increasing preparation time. Access to the patient is thus impaired, which, together with a lack of force-feedback, raises safety concerns.
In addition to robotic systems, several hand-held laparoscopic instruments are known. These instruments provide access to the surgical field without the need for an expensive and cumbersome robotic system, but they often provide poor ergonomy to the user.
There are known examples of hand-held, articulated surgical instruments. However, they present significant drawbacks in their designs. For example, one known articulated instrument (ref) must be attached to the user's forearm by a frame, making its use cumbersome and likely tiring, given that every movement must involve the user moving his entire forearm, which needs to be geometrically aligned with the instrument's shaft. Other known articulated instruments (refs) require the manipulation of knobs or similar elements on the device handle to produce corresponding movements in an end-effector. Such arrangement does not allow for a natural replication of user hand movements.
Accordingly, an aim of the present invention is to provide an articulated hand-held medical instrument that allows for a natural replication of user hand movements on the instrument handle at an end effector. The instrument is to allow for good ergonomy and ease of use as compared to known hand-held articulated instruments.